1. Field of the Invention
The present invention relates to an X-ray device for obtaining radiological exposures of the head and jaw region of a patient, of the type having an X-ray source and an X-ray detector for picking up 2D projections of the head or jaw region of the patient. The invention also relates to a medical workplace for diagnostics and for surgical interventions in the mouth, jaw or face region of a patient, employing such an X-ray device.
2. Description of the Prior Art
Radiological exposures of the jaw, X-ray projection exposures of individual teeth, X-ray panorama exposures of the jaw or computer tomography exposures for acquiring 3D images of tissue areas of the head or of the jaw are carried out for diagnosis and for planning dental surgical interventions, tooth implants or interventions in the facial region of a patient. For financial reasons, the latter are only prepared in justified individual cases, for example for planning tooth implants or reconstructive interventions in the face/skull region, for which intervention planning on the basis of 3D images is indispensable. An X-ray computed tomography apparatus is a relatively expensive image pickup device, and only very few dental surgeons have such a device, so the planning and implementation of a dental surgical intervention normally requires a number of process steps, which do not follow immediately after one another and which may not all be performable by the dental surgeon. For planning and implementing a tooth implantation, the following is necessary, for example:
a) preparing overview exposures of the jaw at the dental surgeon,
b) if needed, obtain images of the jaw done with an X-ray computed tomography apparatus at a radiologist,
c) transferring the computed tomography data to the dental surgeon,
d) planning the intervention at the dental surgeon
e) performing the intervention on the patient.
For example, German OS 40 12 627, corresponding to U.S. Pat. No. 5,012,501, describes an X-ray device for picking up panoramic X-ray images of a jaw on X-ray film.
German OS 196 36 354 discloses a device for obtaining optical images of a tooth, in particular.
An object of the present invention is to provide an X-ray device, and a workplace provided with such an X-ray device, which can be economically produced and with which 3D images of the head and jaw region of a patient can be acquired in a relatively inexpensive manner.
This object is inventively achieved in an X-ray device for obtaining radiological exposures in the head and jaw region of a patient, having an X-ray source and an X-ray detector, which can be arranged or are arranged opposite each another such that the central beam of a conical X-ray bundle originating from the X-ray source strikes the X-ray detector approximately centrally, and having an arrangement for moving the X-ray source and the X-ray detector, by motor-adjustment, around an axis for picking up a series of 2D projections of the head or jaw region of the patient, and having a computer for generating a 3D image dataset from the acquired 2D projections. Similar to rotation angiography devices or adjustable C-arm X-ray devices, the inventive X-ray device has an X-ray source which emits a conical X-ray bundle. The X-ray source can be displaced around an axis of the X-ray device together with the X-ray detector. The head of the patient to be examined is normally supported along this axis. During the adjustment motion around the axis, a series of 2D projections is acquired from different projection angles of the head or jaw region of the patient, so that a 3D image dataset can be acquired from the head or jaw region of the patient. The structure of the X-ray device, for example the distance of the X-ray source from the X-ray detector and the adjustment range of the X-ray source and of the X-ray detector, is adapted to the requirements in the mouth, jaw and face region of the patient. The X-ray device therefore can be kept relatively small. The distance between the X-ray source and the X-ray detector preferably is one meter at a maximum. Since relatively economic and proven components can be used in the inventive X-ray device, the X-ray device can be relatively inexpensively produced. Therefore, the cost for equipping a dental surgical office with such an X-ray device is reasonable affordable, so that a dental surgeon, without time delays due to multiple sessions, can carry out the image pickup, the intervention planning, and the intervention at the patient in steps that directly follow one another.
In a version of the invention, the arrangement for adjusting (positioning) the X-ray source and the X-ray detector has two supports to which the X-ray source and the X-ray detector are respectively mounted, which can be motor-adjusted around the axis of the X-ray device and which can be motor-adjusted relative to one another. Such supports can be guided at a track that runs circularly around the axis and that is mounted to the ceiling, for example. In another version of the invention the X-ray source and the X-ray detector are arranged at a carrier fashioned in a U-shaped or C-arm-shaped manner, and the carrier is rotated by a motor-drive around the aforementioned axis which proceeding extends through the carrier. The carrier can be arranged around a vertically proceeding axis when mounted to the ceiling or can be rotated around a horizontally proceeding axis when arranged at a holding device.
In a particularly preferred embodiment of the invention, the motor-adjustment of the supports, or the motorized rotation of the carrier, is effected by at least one digitally controlled drive. The drive is preferably software-controlled, and can be a stepper motor in an embodiment of the invention. This allows precise adjustment of the support relative to one another, or precise rotation of the carrier device, so that different positions of the support or carrier can be repeatedly reached with high exactness. Since the X-ray device can be kept relatively small overall, the structure of the X-ray device exhibits a high rigidity, so that the adjustment movements of the X-ray system can be accurately reproduced.
In a further version of the invention the X-ray detector can be adjusted relative to its support, or relative to the carrier, in the direction of the central beam. In this way, the X-ray detector can be placed relatively close to the head of the patient and the size of the image field therefore can be optimally adjusted for the respective examination case. The X-ray source and the X-ray detector therefore normally move asymmetrically around the axis or the head of the patient during the pickup of a series of 2D projections.
The above object also is achieved in a medical workplace for diagnostics and for surgical interventions in the mouth, jaw, or face area of a patient, having an X-ray device as described above, a patient support and an arrangement for determining the positions of the X-ray device and the patient support relative to one another, and wherein the X-ray device and the patient support are arranged relative to one another in a defined way and can be mechanically adjusted relative to one another in a defined way.
The object also is achieved in a medical workplace for diagnostics and for surgical interventions in the mouth, jaw, or face area of a patient, having an X-ray device, as described above, a patient support and a navigation system for determining the positions of the X-ray device and the patient support relative to one another.
Both embodiments of the medical workplace make it possible for the dental surgeon to simply and conveniently transfer the planning results obtained on the basis of the 3D image data immediately to the patient and to carry out the intervention as a result of the knowledge of the spatial relationship between the X-ray device, and therefore the 3D image dataset generated by the X-ray device, and the patient on which the patient is borne, and normally fixed. Given adjustments of the patient support relative to the X-ray device, and therefore relative to the 3D image dataset, the representation of generated 3D images can be automatically adapted to the modified position of the patient in the course of the intervention as a result of the known spatial relationship between the 3D image dataset and the patient support.
In a version of the invention, a navigation system not only determines the position of the X-ray device and/or of the patient support but also determines the position of at least one instrument used during a dental-surgical intervention, so that the imaging of the instrument into an image acquired by the X-ray device is enabled for supporting the surgical intervention. In this way, the surgeon can navigate an instrument introduced into the body of the patient on the basis of the image information displayed at a display unit, so that an expedient support of the surgical intervention is assured.